Optoelectronic systems are used to measure fluorescence or luminescence emission decay in a sample, and to then determine characteristics of the sample from the detected emission. For example, optoelectronic systems measure decay time and amplitude of a detected emission, and then analyze the measured decay time and amplitude to determine materials in, or characteristics of, the sample.
FIG. 1 is a diagram illustrating an example of a conventional optoelectronic system to measure fluorescence or luminescence emission decay. Referring now to FIG. 1, a synchronously pumped, cavity-dumped dye laser system 24 emits light pulses 25 into a sample (not illustrated) on a sample holder 26, to cause a fluorescence or luminescence emission from the sample.
A photomultiplier tube 28 detects the emission. In FIG. 1, photomultiplier tube 28 is shown in its own housing 29. A boxcar integrator module 30 generates an electrical signal from output of photomultiplier tube 28, and a signal processor module 32 processes the electrical signal, to thereby determine information about the sample. A memory module 34 stores a result of integrator module 30, and is accessed by signal processor module 32.
A pickoff beamsplitter 31 splits off a portion of the light emitted by synchronously pumped, cavity-dumped dye laser system 24 and provides the split off portion to a photodiode (PD) 33. The output of photodiode 33 is provided to a variable delay module 36 that produces a variable delay used to gate boxcar integrator module 36.
Typically, synchronously pumped, cavity-dumped dye laser system 24 repeatedly emits light pulses to create multiple identical decays, improving the signal-to-noise ratio.
In this manner, the optoelectronic system determines information about the sample by analyzing, for example, decay time and amplitude of the detected emission.
A display device module 40 can be provided to display the determined information.
As illustrated in FIG. 1, synchronously pumped, cavity-dumped, dye laser system 24 includes, for example, a cavity-dumped dye laser 35, a modelocked pump laser 37, a modelocker electronics module 39 and a cavity dumper electronics module 41.
Various additional components are typically provided. For example, a lens 42 focuses light emitted from synchronously pumped, cavity-dumped dye laser system 24 on the sample, and a lens 44 collects emission from the sample and focuses the collected emission on photomultiplier tube 28. A filter or monochromator 46 is typically provided. If a filter is provided, the filter would be, for example, a wavelength filter which passes the fluorescence or luminescence light from the sample, and blocks wavelengths from laser system 24. Generally, such a filter would typically be a long-wavelength transmitting filter, which blocks short wavelengths and passes longer wavelengths. A monochromator provides a similar function as a filter, by passing only desired wavelengths.
A baffle 48 could be provided to prevent light or other unwanted emission from laser system 24 from overwhelming photomultiplier tube 28.
The specific operation of the various components in FIG. 1 will not be further discussed in detail herein, as such operation is well-known in the art.
FIG. 2 is a diagram illustrating an additional example of a conventional optoelectronic system to measure fluorescence or luminescence emission dynamics. The optoelectronic system in FIG. 2 uses a detection system based on time correlated single photon counting (TCSPC).
Referring now to FIG. 2, a time-to-pulse-height converter module 50, a multi-channel analyzer module 52 and a signal processor module 54 operate together to determine information about the sample from the emission detected by photomultiplier tube 28. A first stage amplifier 56, a second stage amplifier 58, and discriminators 60 and 62 are also provided. TCSCP detection allows fluorescence and luminescence emission dynamics to be followed down to low levels, often 10−4 of their initial values. This broad dynamic range reveals the non-exponential behavior of luminescence emission from some samples as well as permitting independent measurement of multiple exponential decays. The specific operation of the various components in FIG. 2 will not be further discussed in detail herein, as such operation is well-known in the art.
Unfortunately, the conventional optoelectronic systems in FIGS. 1 and 2 are very large, and can require a fairly large sized room in which to operate.
For example, a typical synchronously pumped, cavity-dumped, dye laser system 24 is a very large system, with many components each typically housed within its own box or enclosure. For example, in FIG. 1, a typical cavity-dumped dye laser 35 and modelocked pump laser 37 each might be, for example, 2 meters long. A typical modelocker electronics module 39 might be, for example 60 centimeters long, 30 centimeters deep and 20 centimeters high. A typical cavity-dumper electronics module 41 might be, for example, 60 centimeters long, 60 centimeters deep and 20 centimeters high.
Further, a typical synchronously pumped, cavity-dumped, dye laser system 24 has high power requirements and is very inefficient.
Moreover, the operation of a synchronously pumped, cavity-dumped, dye laser system 24 requires the use of a vibration isolation table.
In addition, the dye used in cavity-dumped dye laser 35 is toxic and liquid, thereby causing many problems.
In addition, photomultiplier tube 28 would typically be housed in its own housing 29, such as a box or enclosure. Generally, a typical photomultiplier tube 28 in its housing 29 might be, for example, 25 centimeters long, 17 centimeters wide, and 20 centimeters high. A typical photomultiplier tube 28 might be provided with associate drive components (not illustrated) which are, for example, 30 centimeters long, 35 centimeters wide and 10 centimeters high.
The above-described measurements are only general example measurements, and are simply intended to provide a general idea as to the size of various components.
Further, conventionally, boxcar integrator module 30, signal processor module 32, display device module 40, time-to-pulse-height converter module 50, multi-channel analyzer module 52 and signal processor module 54 are provided as separate components, each housed in its own enclosure.
Accordingly, there is a need for a smaller, integrated optoelectronic system in which all the components are enclosed in the same box.